/*	StringTextDocument - The document as edit template for JTextField in the dialog												to setup/edit the board position.	Copyright (C) 2003 The Java-Chess team <info@java-chess.de>	This program is free software; you can redistribute it and/or	modify it under the terms of the GNU General Public License	as published by the Free Software Foundation; either version 2	of the License, or (at your option) any later version.	This program is distributed in the hope that it will be useful,	but WITHOUT ANY WARRANTY; without even the implied warranty of	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the	GNU General Public License for more details.	You should have received a copy of the GNU General Public License	along with this program; if not, write to the Free Software	Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.*/package de.java_chess.javaChess.util;import java.awt.*;import javax.swing.text.*;/** * Description:   This class is used to verify validate inputs in JTextFields *                such as in the setup/edit position dialog *                For further detailed information look at *                core Java 2 part 1 basics, chapter 9.3.2 p.496ff *                (Sun microsystems, Horstmann/Cornell) *                ISBN 3-8272-6016-7, ca. 50 EUR * Copyright:     Copyright (c) 2003 The Java-Chess team <info@java-chess.de> * Organisation:  The Java-Chess team * @author:       Faber * @version 1.0 */public class StringTextDocument extends PlainDocument{	// Constants what to check for	private final int CHECK_FOR_SQUARE    = 0;	private final int CHECK_FOR_EP_SQUARE = 1;	private final int CHECK_FOR_NUMBER    = 2;	private final int CHECK_FOR_CHAR_NUM  = 3;/** * The number of allowed characters */	private int iCharacterCount = 50;/** * Flag whether to check for numbers only */	private boolean bCheckForNumbers = false;/** * The type what and how to check */	private int iType;/** * Constructor * * @param characterCount The number of allowed character to enter in the JTextField */	public StringTextDocument(int type, int characterCount)	{		super();		iCharacterCount = characterCount;		iType = type;	}/** * Constructor * * @param characterCount The number of allowed character to enter in the JTextField * @param checkForNumbers Flag whether the string to enter has to be parsed for *                        numbers >0 only *///	public StringTextDocument(int characterCount, boolean checkForNumbers)//	{//		super();//		this.iCharacterCount = characterCount;//		this.bCheckForNumbers = checkForNumbers;//	}/** * This method has to be overwritten for personal use. The code below is taken * from the source mentioned in the class description */	public void insertString(int offset, String s, AttributeSet attributeSet)		throws BadLocationException		{			if (s == null) return;			String oldString = getText(0,getLength());			String newString = oldString.substring(0, offset) + s + oldString.substring(offset);			if (canBecomeValid(newString))				super.insertString(offset, s, attributeSet);		}/** * Parse the string for number with value > 0 * * @param sNewString The string to parse * @return <code>true</code> when the given string is a number with value > 0 */	private boolean isValid(String sNewString)	{		try		{			int iVal = Integer.parseInt(sNewString);			if ( iVal > 0 )				return true;			return false;		}		catch(NumberFormatException e)		{			return false;		}	}/** * Returns if the new string (after inserting a character or pasted string) is valid * @param s The string to check * @return <code>true</code> if the string is valid, based on the user's conditions *          given in the constructor */	public boolean canBecomeValid(String s)	{		switch ( iType )		{			case CHECK_FOR_CHAR_NUM: // only character count						return ( s.length() <= iCharacterCount && s.length() >= 0 );			case CHECK_FOR_NUMBER: // numbers only						return ( s.length() <= iCharacterCount && s.length() >= 0 ) && isValid( s );			case CHECK_FOR_EP_SQUARE: // a3-d3 and a6-d6 are valid squares for en passant						return ( this.isValidSquare( s, true ));			case CHECK_FOR_SQUARE: // between a1 and h8						return ( this.isValidSquare( s, false ));			default: return false;		}	}/** * Checks the character for being between a and h which limit the chessboard lines * @param charToCheck The character to check * @return <code>true</code> when between a and h */	private boolean isValidLine(char charToCheck)	{		if (( charToCheck >= 'a' && charToCheck <= 'h' )					|| ( charToCheck >= 'A' && charToCheck <= 'H' ))		{			return true;		}		else{			return false;		}	}/** * Checks whether the given string consists of a valid square from a chessboard * between a1 and h8 * * @param sString The string to parse * @param bEnPassantSquare Flag to check for en passant (3rd row) or not * * @return <code>true</code> if square is valid on a chessboard */	private boolean isValidSquare(String sString, boolean bEnPassantSquare)	{		if ( sString.length() <= iCharacterCount && sString.length() > 0 )		{			if ( isValidLine( sString.charAt( 0 )))			{				if ( sString.length() == 2 )				{					if ( bEnPassantSquare == false )					{						if( sString.charAt( 1 ) >= '1' && sString.charAt( 1 ) <= '8' )						{							return true;						}					}					else{						if( sString.charAt( 1 ) == '3' || sString.charAt( 1 ) == '6' )						{							return true;						}						else{							return false;						}					}				}				else{					return true;				}			}			else{				return false;			}		}		return false;	}}